Well, I have noticed that there is an inconsistency between the books and the movies. But it 'did' state that Dooku was very hard-pressed to defeat Grievous, even though the movies depicted him as both a coward and reckless. And then you have the Clone Wars cartoons which make him appear to be very formidable. But I think the books are recognized as cannon as long as they do not conflict with the stories.
Also, Dooku was a political genius in his own right. While it is evident that he was no where near the mastermind that Palpatine was, he was a clever man, and a rational one at that. So it would appear that Dooku's fear of Palpatine was not irrational or without reason. Dooku, who did not even fear Windu, Obi-Wan, or Anakin, generally feared Palpatine, who many consider to be his inferior. But Deus Ex is right. We do not, nor is it likely that we will 'ever', know why Dooku feared Palpatine the way he did.
As for the Mace Windu issue. I have reviewed Palpatine's respective duels with Yoda and Mace numerous times. There is a clear difference between them. The website declares that Palpatine was outmaneuvered. So I doubt this is a lie. However, Palpatine went into the duel and killed three Jedi Masters in a few seconds. And we all know that Palpatine's greatest weakness, as cited by Luke in Return of the Jedi, is his over confidence. Having duped the Council and the Jedi, as well as killing Mace's entourage with relative ease, I assume he went into the duel with Mace a trace over-confident. He went on the offensive. Notice that he didn't use his immense Force powers (which are probably vastly superior to Mace's own). He used his saber skills. While I do not consider Palpatine a pathetic duelist, it is obvious that the Sith Lord's main source of offense and power is his Force powers. Palpatine also took his time. Now. It is utterly conveniant how Anakin mysteriously walked in on the duel, just a second after Palpatine was disarmed.
Perhaps Palpatine did indeed loose to Mace, in the duel. But it is also obvious that he took that loss and made it work where he had Anakin in the position where it would lead him further down the Dark Side. I do not know if Mace would've killed Palpatine without Anakin's interference, but it seems likely.
However. Had Palpatine battled Mace as he did with Yoda, I have no doubt that the Koruun master would be dead. Palpatine's Force powers are immensely developed for a Force-user, and his battle with Yoda showed that he recognized 'the little green freak' as the greater danger. His confidence was probably bulstered after his duel with Mace, hence his reluctance to battle someone with Yoda's attunement and wisdom.
But this is just my theory.